But representatives for Subway, which apparently does not use the chemical in its European or Australian markets, would not say when the company would actually effect the changes.

Although Subway claims the change was already underway, the announcement coincided with an online petition asking Subway to substitute healthier ingredients. The petition, started by Vani Hari, an activist who has targeted other fast food companies over chemical ingredients, had more than 60,000 signatures by the time Subway responded.